Johns Hopkins Children’s Center Experts Share Advice on the Do’s and Don’ts of Pregnancy


Pregnancy cravings are real, but what if a pregnant woman craves fish or what if she craves a hit of marijuana?

In two recent JAMA Pediatrics Viewpoint articles, Johns Hopkins Children’s Center pediatricians provide recommendations on fish,which can be high in mercury and toxic to a developing fetus’ nervous system, and, separately, marijuana consumption while pregnant.

Something’s Fishy: New FDA and EPA Recommendations Vague, Don’t Highlight Benefits of Eating Fish

In 2017, the United States Food and Drug Administration and Environmental Protection Agency recommended that pregnant women consume 8–12 ounces of fish, or two to three servings, per week. They did not, however, identify benefits to neurocognitive development, and should have specified such benefits from fish consumption due to the strong scientific evidence available, says Carolyn T. Bramante, M.D., M.P.H., a general pediatric fellow at the Johns Hopkins University School of Medicine and an author on the Viewpoint.

Neurodevelopment is a specific benefit of fish consumption during pregnancy, says Bramante, and studies show that children of mothers who consumed approximately 21 ounces of fish during pregnancy had higher scores of verbal, motor, memory and overall cognitive development.

The new recommendations imply a higher risk of exposure to mercury linked with fish consumption by stating that risks are present for all types of fish, rather than risk with only the seven types that have the highest mercury levels. This may cause pregnant women to avoid eating fish entirely and miss out on its rewarding benefits of neurodevelopment. Clinicians should educate women of the low risk of too much mercury and explain the strong evidence of neurocognitive benefits.

Blazing with a Bun in the Oven

As marijuana becomes legalized in more areas across the nation, the use of marijuana by pregnant and lactating women is increasing and becoming more accepted by the medical community. In fact, a recent study shows cannabis use among pregnant women has increased from 2.4 percent in 2002 to 3.9 percent in 2014. In light of growing acceptance for marijuana, this Viewpoint urges health care professionals to remain firm in advising abstinence.

Lauren Jansson, M.D., associate professor of pediatrics at the Johns Hopkins University School of Medicine and an author of the Viewpoint, says, “Advice from medical professionals should be consistent: Pregnant and lactating women should be advised to avoid cannabis use and maintain abstinence.” The major component of marijuana, delta-9-tetrahydrocannabinol (THC) can negatively affect the developing fetal system at 14 weeks, such as causing disturbed sleep, memory impairment and aggression. Conducting studies on marijuana use during different stages of pregnancy is necessary to identify and regulate common patterns and effects on fetal brain development, adds Jansson.

To schedule an interview with any of the experts, please contact Kristen West, 410-955-6881,, or Marin Hedin, 410-502-9429,